Fluid-operated free pump with packing device



Sept. 22, 1953 R. F. MOARTHUR FEUID-OPEEAIED EPEE PUMP WITH PACKING DEVICE Filed Jan. Ie, 195o Patented Sept.'\`2y2, 1953 rLUm-oPEaA'rED naar: PUMP wrm PACKING DEVICE Ralph F. McArthur, Huntington Park, Calif., alsignor, by mesneassignmeuts, to Dresser Equipment Co., Cleveland, Ohio, a corporation of Ohio Application January 16, 1950, Serial No. 138,909

3 claim.. (ci. 10s- 46) My invention relates to a fluid-operated free pump having packing means for preventing fluid ilow past the exterior thereof and, more particularly, to a packing device for this or other Durposes, a primaryobject of the invention being to provide an-improved packing device.

A- well pumping system incorporating a uidf operated free pump normally includes at least two tubings set in a' well, which may be an 'oil well, for example. One of the tubings of such a system is adapted to convey an operating uid, such as clean crude oil, under relatively high pressure downwardly to the pumpfto operate it and may be termed a power tubing. ,The other tubing of such a system is adapted to convey the huid discharged by the pump upwardly in the well 'to the surface of the ground and may be termed a production tubing. 'I'he fluid-operated free pump is movable hydraulically through one of the tubings between an operating position at the lower end thereof and the surface of the ground. 'Ihe tubing through which the pump is movable is preferably the power tubing and the pump will be regarded as movable through the power tubing hereinafter for purposes of illustration, although it will be understood that the pump may be movable through either the power or production tubings without departing from the spirit of the invention.

In a well pumping system of the foregoing na-f ture, the operating fluid is admitted to the pump from the power tubing at a point adjacent the upper end ofthe pump and the fluid discharged by the pump is discharged into the power tubing at a point or points below the point of operating nuid intake. In order to permit flow of the fluid discharged by the pump from the power tubing into the production tubing', the two tubings are conventionally interconnected in uid communication at their lower ends. Consequently, it is necessary to provide a packing device for separating the 'operating and production fluid columns, i. e., to prevent ilow between the operating and production iluid columns through the annular clearance between the exterior of the pump and the interior of the power tubing, which is the purpose of the present invention. f

Normally, the operating and production fluid columns are separated by a packing device, which may be a simple O-ring, adapted to engage a relatively short sealing collar in the line of the power ltubing when the pump is in its operating position. 'I'he internal diameter of the sealing echar is preferably less than the internal diameter of the power tubing as a whole so that a clearancey is provided between the O-ring and the internal wall of the power tubing when the O-ring is out of engagement with the sealing collar. This prevents damage to the O-ring during movement of the pump between its operating position and the surface of the ground. However, in some instances it is desirable to connect an attachment to the lower end of the pump so that the 0-ring normally lseparating the'operating and production fluid columns is located above the sealing collai when the pump is in its operating position, whereupon the 0-ring can no longer serve as a separating means for the two columns. Consequently, it is an important object of the present invention to provide a huid-operated free pump having a substitute packing device thereon for separating the operating and production fluid columns when the packing devicenormally employed is inoperative. n

Another object is to provide a fluid-operated free pump having thereon a ,packing device which, is disposed between the point of operating fluid intake and the point or points of ilud discharge and which is adapted to engage the internal wall of the power tubing at a point above the sealing collar.

Another object is to. provide a packing device which includes a packing element of a readily deformable material which is adapted to expand yradially into huid-tight engagement with the internal wall of the power tubing upon application .of a fluid pressure thereto.

Another important object of the invention is to provide a packing device including a main backing element which is disposed on the low pressure side of the packing element and which is also formed of a deformable material so that it is capable of engaging the internal wall of the power tubing in a positive manner to prevent extrusion of the material of the packing element therepast upor; application of pressure to the packing elemen An object related to the preceding one is to provide-a main backing element which is formed of a material that is less deformable that that of the packing element so as to minimize any tendency of the main backing element to extrude.

extrusion of the main backing element between the auxiliary backing element and the power tubing.

. The foregoing objects of the present invention, together with other objects thereof which will become apparent, may be attained through the utilization of the exemplary embodiments of the ininvention which are illustrated in the accompanying drawing and which ,are described in detail hereinafter. Referring to the drawing:

Fig. 1 is a utility view of a fluid-operated free pumping system which embodies the invention;

Fig. 2 is an enlarged, vertical sectional view taken along the broken line 2-2 of Fig. 1;

Fig. 3 is a transverse sectional View taken along the broken line 3-3 of Fig. 2;

Fig. 4 is a vertical sectional view which is similar to Fig. 2 but which illustrates another embodiment of the invention; and

Fig. 5 is a transverse sectional view taken along the broken line 5 5 of Fig. 4.

Referring particularly to Fig.'1, the numeral I 8 indicates a well casing which may be set in an oil well, for example, and which is open at its lower end to an oil producing formation adjacent the well. Extending downwardly into the well casing l are power and production tubings II and I2 which are threaded at their lower ends into a tting I3, having therein a passage I4 for interconnecting the power and production tubings in uid communication. In the particular construction illustrated, a gas anchor i encloses the lower ends of the production tubings I and I2 and the tting |3 and is secured to the fitting I3 by a bolt I6. Seated in the fitting I3 in alignment with the power tubing I I is a standing valve assembly |`I which provides a seat for a uidoperated free pump |8 having an attachment I8 connected to its 1ower end. As is well known in the art, the pump I8 is movable hydraulically between the surface of the ground and its operating position wherein it is seated on the standing valve assembly I1, the lpump Abeing movable through the power tubing II from the surface into its operating position by an operating fluid pressure applied to the upper end thereof, and being movable from its operating position to the surface by an operating fluid pressure applied to the lower end thereof by way of the production tubing I2 and the passage Il. Fluid flow past the pump during movement upwardly through the power tubing Il is prevented by packers 20 on a packer mandrel 2| which extends upwardly from the body of the pump. The packers 28 are conventional and form no part of the present invention.

Disposed in the line of the power tubing is a sealing collar 22 which, in eect, constitutes a coupling between two sections of the power tubing. Pressed or otherwise secured in the sealing collar 22 is a liner 23 having'an internal diameter which is less than that of the power tubing. When the pump I8 is used in the normal manner without the attachment I9, the columns of fluid in the power and production tubings II and |2 are separated by a packing means, such as an 0- ring 24, which engages the inner periphery of the liner 23, the O-ring being carried by the pump between the point of operating fluid intake and the point or points of fluid discharge so as to prevent intermingling of the operating and production iiuid columns by way of the annular clearance provided between the pump and Fig. l, when the attachment I8 is employed in commotion with the pump I8, the Q-ring 2l is located above the liner 23 so that it is inoperative to separate the operating and production uid columns. the reason for this being that, as previously indicated. the external diameter oi' the 0ring is preferably less than the internal diameter of the power tubing so as to prevent damage to the o-ring during movement of the pump between its operating position and the surface of the ground.

In accordance with the present invention, the pump I8 carries a packing device 30 which is located between the point of operating fluid intake andthe point or points of uid discharge and which engages the internal wall of the power tubing II to separate the operating and production iluid columns when the 0-ring 24 is inoperative to do so. Referring particularly to Fig. 2, the packing device 38 includes a packing element 3| which encompasses the packer mandrel 2| and which engages the lower end of a sleeve 32 encompassing and suitably securedto the packer mandrel to prevent upward movement of the packing element along the mandrel. The packing element 3| is generally cup-shaped and is positioned on the mandrel 2| with its open end facing upwardly toward the higher pressure applied thereto, i. e., toward the operating fluid column. The packing element 3| is provided adjacent its rim with an annular surface 33 which lightly engages the internal wall of the power tubing II when the fluid pressures above and below the packing element are substantially equal. The packing element 3| is formed of a readily deformable material of a rubber-like nature, a rubber-like material, such as neoprene, 1 which is oil resistant preferably being employed for oil well pumping systems.

Since the cup-shaped packing element 3| faces upwardly toward the operating fluid column, it will be apparent that, when the pressure of the operating fluid is increased to a relatively high value to operate the pump I8, the annular portion 34 of the packing element is deformed radially outwardly into fluid-tight engagement with the internal wall of the power tubing so as to separate the operating and production fluid columns, which is an important feature of the invention. In order to prevent downward extrusion of the material forming the packing element 3| by the relatively high operating fluid pressure thereabove, I provide the packing device 3l with a deformable main backing element 31 which is preferably formed of a relatively soft metal such as copper, for example. In the embodiment under consideration, the main backing element 3'I is also generally cup-shaped and faces in the same direction as the cup-shaped packing element 3| with its rim 38 deformed inwardly and embedded in the material of the packing element. As will be apparent, since the packing element 3| is formed of a readily deformable material of a rubber-like nature, the base portion 39 of the packing element is compressed longitudinally by the operating fluid pressure thereabove with the result that the base portion of the packing element expands radially outwardly. Such radially outward expansion of the base portion 39 of the packing element 3| deforms the main backing element 3l radially outwardly into engagement with the internal wall of the power tubing so as to reduce substantially to zero any annular clearance through which the material of the packing element 3| might be extruded by the operating fluid pressure thereabove, which is an important feature of the invention.

The cup-shaped main backing element 31 is provided with an annular base portion l2 seated against a substantially nondeformable, auxiliary backing element 40 which encompasses the packer mandrel 2l and which is in turn seated against a fitting 4| threaded4 onto the upper end of the body of the pump Il. 'I'he fitting Il provides a recess 43 into which a sleeve portion 4l of the main backing element 31 and an annular portion l5 of the packing element 3l extend, this arrangement providing a fluid-tight seal with the backing element I0. /The auxiliary backing element 40 serves to prevent downward extrusion of the main backing element l1. which is another important feature of the invention.v Since the main backing element 31, while deformable, is materially less deformable than the packing element 3|, an appreciable clearance between the auxiliary backing element Ill and the internal wall of the power tubing I l may be provided, such clearance being desirable to facilitate movement of the pump I8 through the power tubing, and particularly through sections of the power tubing which are 'of smaller internal diameter than the nominal value. A y

It will be understood that when the pump I8 is being moved through the power tubing II, the

fluid pressures above and below the packing de-v Ivice Il are approximately equal, in which case the parts of the packing device assume substantially the positions shown in Fig. 2 so that the packing element 3l engages the internal wall of the power tubing Il only lightly'throughout the v area of the annular surface 33 so as to minimize wear of the packing element when running the pump into and out of the well. vThe packing element 3l may not engage the power tubing Il at all when the pump is being run out of the well in particular, the reason for this being that the uid pressure applied to the lower end of the pump to move it upwardly out of the well tends to deform the annular portion 34 of the packing element llinwardly out of engagement with the power tubing. In this case, the pressure applied to the pump to move it upwardly acts on the aforementioned packers 20. y

Referringv to Figs. 4 and 5, the embodiment of the invention illustrated therein is similar tothat Y discussed previously and corresponding parts are identified by corresponding reference numerals plus the suffix a. 'I'he packing device 30a differs from the packing device 30 principally in the main backing element 31a, the latter comprising a pair of superimposed, annular, wire-brushlike members 42a which encompass the packer mandrel 2 la and which engage the internal wall of the power tubing Ila. Each wire-brush-like member 42a comprises a plurality of U-shaped bristles which are looped around an annulus 43a and which extended radially outwardly into engagement with the power tubing lla. After the U-shaped bristles have been placed on eachfannulus Ila, they are retained thereon by an annular element a of channel shaped cross section. 'I'he two members 42a are held in place by being clamped between the lower end of the base portion 39a of the packing element lla and the upper end of the auxiliary backing element 40a.

Preferably, the diameter of the members 42a is normally slightly greater than the internal diameter of the power tubing Ila so that, whenthe pump Ila is inserted into the power tubing, the bristles of the members 42a are bent upwardly or trail slightly. Consequently, when the packing element 31a is deformed longitudinallyby the operating fluid pressure thereabove, it engages the bristles of the members 42a and tends to some extent to return to horizontalness, thereby increasing the bearing pressure at the interface between the bristles and the internal wall of the power tubing. This insures that the main backing element 31a will prevent extrusion of the packing element Sla. As in the previous embodiment, the members 42a of the main backing element 31a are materially less deformable than the packing element 3| a so that, while the auxiliary backing element a prevents extrusion of the members 42a, an appreciable clearance between the auxiliary backing element Illa andthe power tubing Ila may be provided to facilitate move- 4ment of the pump Isa through the power tubing.

out departing from the spirit of the invention and Y I I hereby reserve the right to all such changes, modications and substitutions as properly come within the scope of the invention.

I claim as my invention:

l. In a well pumping system which includesva tubing set in the well and provided with a seat and a sealing collar above said seat, and which includes a fluid-operated free pump movable through said tubing between an operating position at the lower end thereof and the surface of the ground, the external diameter of said pump being less than the internal diameter of said tubing to provide an annular clearancetherebetween, said pump being adapted to seat on said seat and carrying a sealing element which engages said sealing collar when said pump is seated on said seat, the internal diameter of said sealing collar and the diameter of said sealing element being less than the internal diameter of said tubing4 to prevent engagement of said sealing element with said tubing, and said pump having an attachment connected to the lower end thereof and adapted to seat on said seat so that said sealing element is spaced above said sealing collar when said attachment is seated on said seat, the combination of: an annular packing element carried by said pump above said sealing element and engageablewith said tubing to prevent iluid flow through said annular clearance between said pump and said tubing, said packing element being formedmof a deformable material; and backing vmeans caiedby said pump below and in contact with said packing element.

2. The combination defined in claim 1 wherein said backing means includes a main backing element for said packing element disposed below and in contact with said packing element and formed of a deformable material which is less deformable than that of said packing element, said backing means including an auxiliary backing element below and in contact with said main 7 backing element and formed of a substantially nondeformable material.

3. In a well pumping system which includes a tubing set in the well and provided witha seat and a sealing collar above `said seat. and which includes a duid-operated free pump movable through said tubing between an operating position at the lower end thereof and the surface of the ground, the external diameter of said pump engages said sealing collar when said pump is seated on said seat, the internal diameter of said sealing collar and the diameter of said sealing element being less than the internal diameter of said tubing to prevent engagement o! said sealing element with said tubing, and said pump having an attachment connected to the lower end thereof and adapted to seat on said seat so'that said sealing element is spaced above said sealing collar when said attachment is seatedon said seat, the combination with the foregoing elements of an annular sealing means carried by said pump 8 above saidV sealing element and ensageable with said tubing to prevent uid now through said annular clearance between said pump and said tubing, said sealing means being expansible radially into engagement'with said tubing by pressure thereabove.

RALPH F. McAaTHUR.

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